Self-adjusting spindle bearing



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/ SELF ADJUSTING SPINDLE BEARING Filed April 15, 1936 5 Sheets-Sheet l Aug. 23. 1938.

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ADJUSTING SPINDLE BEARING Filed April 15, 1956 5 Sheets-Sheet 4 f J5 dz 1 Wm wrz y fdlkkon Aug. 23, 1938. s. w. BATH ET AL SELF ADJUSTING SPINDLE BEARING 5 Sheets-Sheet 5 Filed April 15, 1936 for/8y Warm air iv 31% Patented Aug. 23, 1938 UNITED STATES,

PATENT OFFICE SELF-ADJUSTING SPINDLE BEARING of Massachusetts Application April 15, 1936, Serial No. 74,526

1 Claim.

This invention relates to bearings for spindles which must be run at high speed with the least possible vibration. While capable of general application, our invention is particularly adapted 5 for use in mounting a grinding wheel spindle in a grinding machine.

It is the general object of our invention to provide an improved construction of spindle bearing such that end play as well as transverse 10 vibration of the spindle is substantially eliminated.

A further object is to provide a construction in which this cooperative relation of spindle and bearing will be automatically maintained over a 15 long period. of use and wear.

We also provide a constructionwhich is selfadjusting over a substantial range, so that extremely close and accurate fitting of parts is not required. Our invention is thus economical in 20 manufacture and is extremely reliable and effective in use.

Our invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed 25 out in the appended claim.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a front View of our improved spindle and bearing;

Fig. 2 is a sectional front elevation of the same parts, taken along the line 2-2 in Figs. 3 and 10;

Fig. 3 is a plan view, looking inthe direction of the arrow 3 in Fig. 1;

Fig. 4 is a plan view of the bearing with the 35 spindle and bearing caps removed;

Fig. 5 is a front elevation of the spindle;

Fig. 6 is a sectional end elevation, taken along the line 6-6 in Fig. 3;

Fig. '7 is a detail plan view with cover plate removed, looking in the direction of the arrow 1 in Fig. 6;

Figs. 8 and 9 are partial sectionalviews illustrating certain steps in the manufacture of the 45 ffriit bearing bracket and cap;

Fig. 10 is a sectional end elevation, taken along the line Ill-I0 in Fig. 3;

Fig. 11 is a side elevation of the rear bearing blocks;

50 Fig. 12 is a partial plan View, looking in the direction of the arrow l2 in Fig. 11;

Fig. 13 is a detail sectional view, taken along the line l3-l3 in Fig. 12;

Fig. 14 is a side elevation of the upper front 55 bearing block;

Fig. 15 is a similar view of the lower front bearing block;

Fig. 16 is a detail plan view, looking in the direction of the arrow It in Fig. 14;

Fig. 17 is a detail sectional View, taken along 5 the line ll-|1 in Fig. 16;

Fig. 18 is a plan view of the lower front bearing block, looking in the direction of the arrow l8 in Fig. 15;

. Fig. 19 is a detail front elevation, partly in 10 section, looking in the direction of the arrow IS in Fig. 6; I

Fig. 20 is a partial side elevation of an end disc, looking in the direction of the arrow 20 in Fig. 19, and 15 Fig. 21 is a detail partial sectional elevation, taken along the line 21-2! in Fig. 20.

Referring to the drawings, our invention comprises a stand 25 adapted to be bolted to a machine frame or other suitable support. The 20 stand 25 is provided with a front bearing bracket 26 (Fig. 4) and a rear bearing bracket 21 and these supporting brackets are provided with bearing caps 28 and 29 secured to the brackets 26 and 21 respectively by clamping screws30, as 25 shown in Figs. 6 and 10.

Front upper and lower bearing blocks 32 (Fig. 14) and 33 (Fig. 15) are mounted on the front bearing bracket 26 and are held from displacement by the front bearing cap 28. upper and lower rear bearing blocks 35 and 36 (Fig. 11) are mounted in the rear bearing bracket 21 and are secured from displacement by the rear bearing cap 29.

The front and rear bearing blocks above de- 35 scribed support a wheel spindle 40 (Fig. 5) hav-. ing a straight bearing portion 4|, a double conical bearing portion 42 and a counterbalance portion 43. A grinding wheel W is shown clamped to one end of the spindle 40 and a driving pulley 44 is 40 shown secured to the other end of the spindle.

We will first describe the, rear bearing for the spindle 4B. As previously stated, upper and lower rear bearing blocks 35 and 36 (Fig. 11) are provided for the rear straight or cylindrical bear- 45 ing portion 4|. These blocks are provided with an external flange 46 (Fig. 13) having a circumferential groove 41. Otherwise the external surfaces of the bearing blocks 35 and 36 are cylindrical, as indicated at 4B in Fig. 13, and fit close- 50 ly within an internal cylindrical opening in the assembled rear bearing bracket 2! and cap 29. (Fig. 2). This internal cylindrical surface is grooved as shown at 49 (Fig. 2) to receive the grooved flange 46 on the blocks 35 and 36.

Similarly, 30

The bearing blocks and 35 are firmly secured in position by a plurality of clamping screws (Fig. 10), and the ends of the rear bearing are closed by end discs 52 (Fig. 2) firmly secured in place at each face of the bearing by cross bolts 53. Each disc 52 is preferably internally grooved as indicated at 54 (Fig. 21) to receive an oil seal washer 55 of felt or other suitable material.

Special provision is made for effective lubrication of the rear bearing. The upper rear bearing block 35 is provided with an oil pocket 5? (Figs. 11 and 13) which, when the parts are assembled, is aligned with an oil hole 58 in the rear bearing cap 29, which hole may be closed to exclude dirt by a screw or plug 59.

The oil pocket 571' has end openings 58 (Fig. 13) communicating with a slot 6| in the internal bearing surface of the block 35. The slot GI and openings 60 are preferably filled with a wick of felt or some other suitable oil conducting material, which wick directly engages the surface of the straight bearing portion 4! of the spindle 45.

The rear bearing bracket 21 is provided with a segmental oil pocket (Fig. 10) which connects through radial oil openings 65 in the lower bearing block 35 with a transverse slot 66 formed in the internal bearing surface thereof.

The slot 56 and openings 55 are preferably filled with a wick felt or similar material 6? as previously described, and the outer end of the wick 6'! extends into the oil pocket 5:1. The pocket 64 is filled by overflowing the upper oil pocket 51, so that oil Will flow around the circumferential groove 41 to the pocket 64. A very small bleed opening 68 in one of the end discs 52 indicates by slight escape of oil therefrom that the lower pocket 64 is amply supplied with oil.

A transverse notch 59 (Fig. 11) is formed in the flange 46 and coacts with a groove I5 (Fig. 10) in the internal surface of the bracket to form an equalizing channel through which oil may flow freely from one side to the other of the bearing block 36.

A removable screw or plug II closes a bottom opening I2 through which the oil pocket 64 may be drained when desired.

While the rear spindle bearing as above described is more or less conventional, except for the described details of construction and lubrication, the front bearing is of a quite special construction which will now be described.

The upper face of the supporting bracket 26 (Figs. 6, 8 and 9) is cut away or recessed at the sides as indicated at I5 to receive downwardly projecting edge portions 16 on the lower face of the cap 28. It will be noted by reference to Figs. 6, 8 and 9 that the projections on the cap are spaced further apart than the recessed portions I5 of the bearing bracket 26.

These parts 25 and 28 are first assembled as indicated in Fig. 8, in which position an internal cylindrical opening I1 is produced by boring or in any other convenient manner.

When the parts are assembled, however, the cap 28 is moved over to the position indicated in Figs. 6 and 9, and is firmly secured in this offset position by the screws 3ll previously described.

The lower front bearing block 33 (Fig. 15) is provided with an annular flange I8 having a groove "I9 similar to the rear bearing blocks previously described, and the internal surface 'I'! of the front bearing bracket 25 is similarly grooved as indicated at 30 (Fig. 6) toreceive the flange I8.

The lower front bearing block 33 is secured in position by clamping screws 8| and 82 (Fig. 6) and is provided with a segmental V-shaped bearing recess 84 (Fig. 18) having an annular clearance groove 85 at the apex thereof.

The upper front bearing block 32 has a similar segmental V-shaped bearing recess 8? (Fig. 17) and clearance groove 88, but the recess 81 and groove 88 in the upper front bearing block 32 are substantially eccentric to the outer surface of the block 32, which outer surface is of the same external radius as that of the lower front bearing block 33 and correspondingly fits the internal cylindrical opening 'I'. of the bracket 28.

A stud 85 (Fig. 6) is secured to the upper front bearing block 32 and projects outward into a recess 9! formed in the bearing cap 28. A sleeve 92 is slidably mounted in a transverse cylindrical opening 93 formed in the cap 28 and communicating with the recess 9|.

The sleeve 92 is provided with a head G l and may be secured in axially adjusted position in the opening 93 by a set-screw 55. A coil spring 95 is connected between the stud 99 previously described and an attachment stud 9'1 mounted in the head 94. A removable cover plate 33 is provided for the recess 9|.

The function of the spring 93 is to give the upper front bearing block 32 an impulse to move angularly in a clockwise direction as viewed in Fig. 6, this movement being opposite to the direction of rotation of the spindle 4-0, which is indicated by the arrow (1 in Fig. 6.

The upper front bearing block 32 is provided with an oil pocket I55 which receives oil through an oil hole IUI in the cap 28. The block 32 is also provided with slots on the inner inclined bearing surfaces thereof, and wicks of felt or other similar material are placed in these slots as indicated at I52 (Figs. 2 and 6) and extend upward into the oil pocket I50.

A lower oil pocket N34 is formed in the front bearing bracket 26 and receives oil by overflow from the oil pocket IEO as previously described in connection with the rear bearing. The lower front bearing block 33 is similarly slotted to recelve a wick or felt I06 (Figs. 4 and 6) and the lower part of the wick I06 extends into the oil pocket I04.

End discs 52 are provided, as for the rear bearing, and a bleed opening Ill? is provided in one of the discs to show when the pocket I94 is amply provided with oil.

A transverse groove or notch I I 5 in the circumferential flange of the lower front bearing block 33 and a similar groove or notch III in the associated part of the bearing bracket 26 (Fig, 6) coact to equalize the oil distribution at opposite sides of the front bearing, all as previously described.

Having described the details of construction of our improved spindle and bearing, the method of operation and advantages thereof are believed to be readily apparent. The rear bearing which is remote from the wheel W acts as an ordinary cylindrical bearing, and is of reasonably but not excessively close fit.

The front bearing with its V-shaped bearing surfaces obviously positions the spindle axially and entirely prevents end play.

Furthermore, the spring 96 (Fig. 6) tends constantly to rotate the upper front bearing block 32 in a direction to more closely engage the double conical bearing surface of the spindle Ill, while the rotation of the spindle in a direction opposite to the pull of the spring 96 prevents the eccentric bearing block from being moved by the spring far enough to bind the spindle.

mid-position where these opposing forces are balanced, and in this position the eccentric upper front bearing block effectively prevents transverse vibration of the spindle. When the bearing surfaces begin to wear, the block 32 merely adjusts itself slightly further to the right as viewed in Fig. 6.

Our improved bearing is thus self-adjusting over long periods of use, and requires practically no attention except for oiling. If there is any slight suggestion of transverse vibration, this may be immediately remedied by increasing the tension of the spring 96,. which is accomplished by pulling out the tube 92 and securing it in a new adjusted position by the set-screw 95. Similarly, if the bearing tends to heat, the tension of the spring may be slightly relieved by adjustment in the opposite direction.

It will be noted that all parts of our improved bearing are easily constructed and that expert fitting and close adjustment of the bearing parts is reduced to a minimum.

Having thus described our invention and. the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what we claim is:-

In a machine tool, a spindle having a normal direction of rotation and a bearing therefor comprising a bearing support and a cap having internal segmental cylindrical surfaces of equal radius, means to secure said support and cap together with the axis of one cylindrical surface offset laterally from the axis of the other cylindrical surface, a fixed bearing member having concentric inner and outer surfaces and secured in said support, a movable bearing member having eccentric inner and outer surfaces and mounted for angular movement in said cap but with the axes of the inner surfaces of said fixed and movable members concentric and with said inner surfaces in direct bearing engagement with said spindle, and a spring to move said movable bearing member in a direction opposite to said normal direction of spindle rotation to an angular position in which the force of said spring is balanced by the frictional drag of the spindle on said movable bearing member.

STANLEY W. BATH. HARVEY M. ALLISON. 

